The invention relates to novel metal complexes with formula 1, where    M denotes ruthenium or osmium,    L denotes a neutral ligand, selected from the group comprising amines, imines, phosphines (preferably stilbines, arsines, alcohols, thiols, ethers and thioethers or the N-heterocyclic carbene ligand (NHC) represented by formula 9, where            B denotes the methylene (—C—), 1,2-ethylene (—C—C—), 1,3-propenyl (—C—C—C—), 1,2-ethenylene (—C═C—) or azaethenyl (—N═C—) residue, unsubstituted or substituted with halogens, C5-C24 aryl, C1-C6 alkyl, C1-C13 perfluoroalkyl, C1-C6 cycloalkyl groups, moreover the alkyl groups may be joined together in a ring; preferably B denotes 1,2-ethylene (—CH2—CH2—)        R and R′ denote, independently of one another, C5-C24 aryl, C5-C24 perfluoroaryl, C1-C26 alkyl, C1-C26 perfluoroalkyl, C1-C7 cycloalkyl groups, unsubstituted or substituted with halogens, C5-C24 aryl, C1-C6 alkyl, C1-C13 perfluoroalkyl, C1-C6 cycloalkyl groups, moreover the alkyl groups may be joined together in a ring, preferably R and R′ denote, independently of one another, phenyl groups substituted with C1-C26 alkyl residues, most preferably 2,4,6-trimethylphenyl        X and X′ denote an anionic ligand, selected independently of one another from the group comprising anions of halogens, the phenolate anion (C6H5O−) and perfluorophenolate anion (C6F5O−), residues of arylcarboxylic, alkylcarboxylic, perfluoroalkylcarboxylic, alkylsulphonic, arylsulphonic, perfluoroalkylsulphonic acids, preferably chlorine            R1 denotes hydrogen, C1-C5 alkyl, C2-C5 alkene or C3-C7 cycloalkyl, preferably hydrogen    R2, R3, R4, R5, R6, R7 denote, independently, C1-C25 alkyl, C1-C25 perfluoroalkyl, C5-C24 aryl, C2-C25 alkene or C3-C7 cycloalkyl, the nitro (—NO2), cyano (—CN), carboxyl (—COOH), ester (—COOR″), sulphone (—SO2R″), formyl (—CHO), sulphonamide (—SO2NR″2), or ketone (—COR″) group, in which groups R″ has the following meaning: C1-C5 alkyl, C1-C5 perfluoroalkyl, C5-C24 aryl,    A denotes either nitrogen or carbon placed with an R5 group having the meaning given aboveand a method of production thereof.
Compounds of formula 1 occur as two isomers: with formula 1a, in which atoms X and X′ are arranged trans relative to one another (see for example FIG. 1), and with formula 1b, in which atoms X and X′ are arranged cis relative to one another (see for example FIG. 2). The invention also relates to the use of the compounds of formula 1, both as the pure isomers with formula 1a and with formula 1b and of mixtures thereof, as (pre)catalysts in processes of metathesis.
In applications of metathesis of olefins in organic synthesis, much progress has been achieved in recent years especially in the fields of organic chemistry and polymer chemistry. Practical applications, especially on an industrial scale, require these complexes to be stable for a prolonged time in conditions of elevated temperature and it should be possible to store, transport and use them without a protective gas atmosphere. Rapidly initiating (pre)catalysts, for example of formula 2, in which Mes denotes 2,4,6-trimethylphenyl, are often characterized by lower thermal stability. In addition, some metathesis reactions, especially polymerizations (ROMP, ADMET), are difficult to control in the case of rapidly initiating (pre)catalysts. For this reason it may be advantageous to use (pre)catalysts that are characterized by a lower rate of initiation of the metathesis reaction and that possess high thermal and chemical stability (Organometallics 2005, 24, 2255). This group of (pre)catalysts has found application in particular in polymer chemistry, as initiators permitting controlled polymerization. Representatives of such (pre)catalysts are the pyridine derivatives represented by formula 3, in which iPr denotes isopropyl (Journal of Organometallic Chemistry 2000, 606, 65) and 4 (Organometallics 2004, 23, 5399).
It was found, unexpectedly, that the novel complexes of ruthenium and osmium according to the invention represented by formula 1 are particularly advantageous as (pre)catalysts, they display a low rate of initiation in ring-closure metathesis, and permit a controlled reaction of polymerization by ring opening, while displaying unusually high thermal stability and resistance to oxygen and moisture.